(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Chemical and physical properties of organic phosphorus insecticides"

December 1951 E-832 

United States Department of Agriculture 

Agricultural Research Administration 

Bureau of Entomology and Plant Quarantine 



CHEMICAL AND PHYSICAL PROPERTIES OF 
ORGANIC PHOSPHORUS INSECTICIDES 

By Fred I. Edwards, Division of Insecticide Investigations 



Several organic phosphorus compounds have recently come into use 
as insecticides, and a number of others have been proposed for this 
purpose. The physical and chemical properties of these compounds are 
presented herein for the guidance of investigators working with them. 
The information has been compiled from the literature, from data 
supplied by manufacturers, and from measurements made in this 
laboratory. Only the compounds that are now in commercial use or 
are being tested extensively are included. 

All these compounds are highly toxic to man, and caution should be 
used in handling them. 



Literature Cited 

(1) Hall, S. A. 

1950. Methyl homolog of parathion. Amer. Chem. Soc. Jour. 

72: 2768-2769. 

(2) and Jacobson, M. 

1948. Hexaethyl tetraphosphate and tetraethyl pyrophosphate. 
Ind. Eng. Chem. 40: 694-699. 

(3) Schrader, G. S. 

1951. Die Entwicklung neuer Insectizide auf Grundlage 

organischer Fluor- und Phosphor-verbindungen. 
Monograph No. 62, p. 52. Verlag Chemie, GMBH, 
Weinheim, Germany. 

(4) Toy, A. D. F. 

1948. Preparation of tetraethyl pyrophosphate and other tetraethyl 
pyrophospates. Amer. Chem. Soc. Jour. 70: 3882-3886. 



Structural formula. 



Other names 



0,0-Diethyl O-p-nitropbenyl 
thiophosphate 



Empirical formula 
Molecular weight. 
Phosphorus content 
Physical state . 
Melting point . . 
Boiling point . . 
Specific gravity 

Refractive index 

Solubility in water 
Hydrolysis rate . 




C 2 H 5 Q S 

^P-O- 

C2H5C/ 



Parathion, E-605 

C 10 H 14 NO 5 PS 

291 

10.63% 

Pale-yellow liquid 

6.0°C. 

157-162°C. at 0.6 mm 

1.2655 at 25°/4°C. 



N0 2 



n 



25 
D 



1.5370 



15-20 p. p.m. at 20-25°C. 

Very slow at pH 7 and below. Half- 
life 120 days at 25°C. 

Very rapid above pH 7. Half- life 
8.6 m in. in N/'l alkali at 30°C. 



0,0-Dimethyl O-p-nitro 
thiophosphate 



CH30 2 

x p-o 



CH30 



/ 



-NO, 



Methyl parathion, methyl h| 

parathion 
C 8 H 10 NO 5 PS 

263 

11.78% 

White crystalline solid 

35°(l)f ^OC^)- 7 

1.358 at 20°/4°C 

35 
n D 1.5515 

50 p. p. m. at 25°C. 

Stable for several days in rlt: 
water. Very rapid in alksne 
solution. Half-life approi; 
2.5 m in. in N/l alkali at 3% 



Structural formula- • 



Other names 



Tetraethyl pyrophosphate 
C2H5P •?, ?/ OC 2H5 

V-o-p( 

C 2 H 5 CK X OC 2 H 5 



Tetraethyl dithiopyropft<p 



C 2 H 5 0j I y OC ? V 

\P-G-P' 
C2H 5 / OC 2 H 



Empirical formula. 

Molecular weight. . 
Phosphorus content 
Physical state . . . 

Melting point. . . . 

Eoiling point. . . . 

Specific gravity . . 

Refractive index 

Solubility in water . 
Hydrolysis rate . . 



TEPP (commercial preparation con- SSulfotepp, dithio, tetraethy 



taining about 40% of tetraethyl 
pyrophosphate) 

C 8 H 2 0O 7 P2 
290 

21.36% 
Colorless liquid 



pyrophosphate 

C 8 H20°5 P 2 S 2 

322 

19.25% 

Yellow to colorless oil 



104-110 C. at 0.08 mm. 
1,1810 at 25°/4°C. 

n ^ 1.4170 (2_)r 1.4180 (4)- 

Completely miscible 

'Rapid- in neutral water; half-life at 

25°C. 6.8 hours; at 38°C. 3.3 hours 



Very rapid in alkaline solution 



110-113 W C. at 0.2 mm 

1,196 at 25°/4°C. 

25 
n^ 1.4753 

670 p. p. m. 
Very stable 



1/ See Literature Cited 



):2nyl 



Diethyl p-nitrophenyl phosphate 



teolog of 



C 2 H 5 0. ° 

\p-o- 



C 2 H 5 ° 



/ V 



NO. 



O-Ethyl O-p-nitrophenylbenzene 
thiophos phonate 
S 



c 2 H 5°\p_o 



"\ 



X 



NO2 



:itral 

me 

?nately 

C. 



Para-oxon, E-60C, oxygen analog of 

parathion 
C 10 H 14 NO 6 P 

275 

11.26% 

Reddish-yellow liquid 

148-151°C. at 1 mm. 
1.269 at 25°/25°C. 

n 2 ^ 1.5060 

2500 p. p.m. at 25°C. 
Very slow at pH 7 




EPN, ethyl p-nitrophenyl thiono- 

benzenephosphate 
C 14 H 14 4 NPS 

323 

9.59% 

Off-white crystals 

36°C. 



Essentially insoluble 
Stable at pH 7 and below; slow 
above pH 7 



phate 



Octamethyl pyrophosphoramide 



(CH 3 ) 2 N ^ V N(CH 3 } 2 

>p-o-p x 

\N(CH 3 ) 2 



0,0 -Diethyl 4-methylumbelliferone 
thiophosphate 



\ 



ithiono- 



(CH 3 ) 2 N 



OMPA, schradan 



C 8 H 24 N 4 3 P 2 

286 

21.65% 
Colorless liquid 



C2H50 7 



/ 



P-O 



118-122 U C. at 0.3 mm. 
1.1343 at 25°/4°C. 

n 2 D 1. 4612 

Completely miscible 

Rapid in strong acid solution and very 
slow in neutral and alkaline solutions 



vS 



c=o 

i H 



H3 



Diethyl thiophosphoric acid ester 
of 7-hydroxy-4-methyl coumarin, 
E-838 

Ci 4 H 17 5 PS 

328 

9.44% 

Fine white crystals 

36°C. 

1.260 at 38°/4°C. 
n^ 1.5685 

Very slightly soluble 
Very slow 




UNIVERSITY OF FLORIDA 

llltl III mi 

3 1262 09239 6158 



Q 
i 

O 
O 



co 
X 

u 



o 

CO 

X 

o 



CO 



I 

CO 



U 



CO . ^ t— lO u 

co cd Q \ r-* 



mQ in "O 



CO 

3 

O 
P 
In 
-t-> 

CO 



s 

co 

c 

x: 

-4-> 

o 



a) 

u 

c 



c 

•H O 

CD O 



ro 



rf ^ 

- £ 



cd 



cd 



■r, 



3 -C 

o a 



u 

9, cd 



5 5 



CJ 



o 

a 

OJO 

c 



n <D I/) 1/5 ^ 

w S cu 0, § 



o 
a 

tup 

c 



o 

CQ 



> 

CO 

u 

CUD 



u 

a 

CO 



X 
4> 

c 

H 

<D 

> 

• ■-( 

O 
CO 

Fh 

<— 

CD 



U 

o 

-t-J 

cd 

-> 



tf CO 



CO 

o 
S-. 
•o 
>>